Upload
earl
View
66
Download
0
Tags:
Embed Size (px)
DESCRIPTION
POPULATION DYNAMICS. POPULATION DYNAMICS. POPULATION POPULATION DEF?? POPULATION ECOLOGY CONCERNED WITH THE CHANGES IN POPULATION SIZE AND THE FACTORS THAT REGULATE POPULATIONS OVER TIME. POPULATION DYNAMICS. POPULATION ECOLOGY . POPULATION DYNAMICS. - PowerPoint PPT Presentation
Citation preview
POPULATION DYNAMICS
POPULATION DYNAMICS
• POPULATION– POPULATION DEF??– POPULATION ECOLOGY• CONCERNED WITH THE CHANGES IN POPULATION SIZE
AND THE FACTORS THAT REGULATE POPULATIONS OVER TIME
POPULATION DYNAMICS
• POPULATION ECOLOGY
POPULATION DYNAMICS
• DENSITY AND DISPERSION PATTERNS ARE IMPORTANT POPULATION VARIABLES– POPULATION DENSITY
• THE NUMBER OF INDIVIDUALS OF A SPECIES PER UNIT AREA OR VOLUME
• IT’S EXTREMELY DIFFICULT TO COUNT ALL THE INDIVIDUALS IN ANY POPULATION, SO SCIENTISTS USE VARIOUS SAMPLING TECHNIQUES– TAG & RECAPTURE METHOD
POPULATION DYNAMICS
• DENSITY AND DISPERSION PATTERNS ARE IMPORTANT POPULATION VARIABLES– DISPERSION PATTERN• REFERS TO THE WAY INDIVIDUALS
ARE SPACED WITHIN THEIR AREA• 3 MAJOR PATTERNS
– CLUMPED– UNIFORM– RANDOM
POPULATION DYNAMICS
POPULATION DYNAMICS
POPULATION DYNAMICS
• IDEALIZED MODELS HELP US UNDERSTAND POPULATION GROWTH– EXPONENTIAL
GROWTH MODEL• RATE OF
EXPANSION OF A POPULATION UNDER IDEAL CONDITIONS; UNREGULATED GROWTH
POPULATION DYNAMICS
• IDEALIZED MODELS HELP US UNDERSTAND POPULATION GROWTH– POPULATION
-LIMITING FACTORS AND THE LOGISTIC GROWTH MODEL
POPULATION DYNAMICS
• IDEALIZED MODELS HELP US UNDERSTAND POPULATION GROWTH– IDEALIZED MODELS DON’T EXIST IN NATURE!!– POPULATION-LIMITING FACTORS• ENVIRONMENTAL FACTORS THAT RESTRICT
POPULATION GROWTH– LOGISTIC GROWTH MODEL• IDEALIZED POPULATION GROWTH THAT IS SLOWED BY
LIMITING FACTORS AS THE POPULATION SIZE INCREASES
POPULATION DYNAMICS• LOGISTIC GROWTH MODEL
– CARRYINGCAPACITY • THE
MAXIMUMPOPULATIONSIZE THAT ANENVIRONMENTCAN SUPPORTAT APARTICULARTIME, WITHNODEGRADATIONTO THEHABITAT
POPULATION DYNAMICS
• MULTIPLE FACTORS MAY ACT AS LIMITING AGENTS– COMPETITION FOR LIMITED RESOURCES
• FOOD, TERRITORY, MATES, ETC.– INCREASED DISEASE TRANSMISSION– PHYSIOLOGICAL FACTORS ARE IMPACTED BY DENSE
POPULATIONS– ABIOTIC FACTORS MAY IMPACT POPULATION SIZE
• *SOME POPULATIONS HAVE “BOOM-AND-BUST” CYCLES*– THIS IS NOT FULLY UNDERSTOOD
POPULATION DYNAMICS
• WHAT DOES THE LOGISTIC GROWTH MODEL REALLY LOOK LIKE IN A STABLE ENVIRONMENT??
POPULATION DYNAMICS
• HUMAN POPULATION GROWTH
POPULATION DYNAMICS
• LIFE TABLES TRACK MORTALITY AND SURVIVORSHIP IN POPULATIONS– SURVIVORSHIP CURVES• PLOT THE
PROPORTION OFINDIVIDUALS ALIVE AT EACH AGE
POPULATION DYNAMICS
• BIRTH AND DEATH RATES AND AGE STRUCTURE AFFECT POPULATION GROWTH– ZERO POPULATION GROWTH (ZPG) IS WHEN
BIRTH RATES EQUAL DEATH RATES
POPULATION DYNAMICS
• BIRTH AND DEATH RATES AND AGE STRUCTURE AFFECT POPULATION GROWTH– AGE STRUCTURE• THE PROPORTION OF INDIVIDUALS IN DIFFERENT AGE-
GROUPS
POPULATION DYNAMICS
• TWO IMPORTANT PRACTICAL USES OF POPULATION DYNAMICS INCLUDE– RENEWABLE RESOURCE MANAGEMENT• HARVESTING CROPS WITHOUT DAMAGING THE
RESOURCE– MAXIMUM SUSTAINABLE YIELD• HARVESTING AT A LEVEL THAT PRODUCES A
CONSISTENT YIELD WITHOUT DAMAGING THE POPULATION
POPULATION DYNAMICS
• THAT’S POPULATION ECOLOGY…BUT HOW DO ALL OF THE DIFFERENT POPULATIONS GET ALONG??
• THAT’S COMMUNITY-LEVEL ECOLOGY, AND THAT’S NEXT!!!